Motorola V300, V500, V600 Service Manual

Triplets Repair Map – Audio

(1)If there is no Tx audio check:

•Microphone

•J1200 connector

•Discrete components around the Mic For dry joints and damage

Replace missing / damaged components

(2)Enter test mode, open audio loop(4*5*1),check :

•INT_MIC_BIAS(2.1V) at R1000

•Check R1000, R1003, C1001, C1005 for dry

joints and damage

If there is no INT_MIC_BIAS then replace U900

(4) If there is no Rx audio, check if it is flip related issue,if not please check:

•J1300 for dry joints

•R1210, R1211

•C1014, C1015, C1017, C1018

For dry joints,skewed part,missing.Replace / reflow discretes as appropriate.

(5)If there is no Rx audio from Headset ,check:

•Handset Jack for damage, bad connectivity

•C1033, C1038

•C1030, L1030, R1030

For dry joints, skewed part, missing. Replace / reflow discretes accordingly.

(3)If there is no Tx audio from Headset, check :

•Handset Jack for damage, bad connectivity

•R1020, R1022, C1020, C1021, L1020 for dry joints, damage

If still no TX audio replace U900.

(6) If still no audio signal (Tx&Rx) ,then it is more likely a IC problem:

•U900(PACP)

•U800(Neptune)

At first replace U900, if not effective then replace U800.

		J1300 U900,U800 INT_MIC_BIAS

J1200

Signal Path Key

Red signal path represents	Blue signal path represents
Tx Audio	Rx Audio